The present invention relates to a process for producing a terbium alloy or terbium metal and, more in particular, relates to a process for continuously producing a terbium alloy or terbium metal with high terbium content and low content of impurities suitable to a starting material, e.g., for a terbium-iron-cobalt system sputtering target.
A process for producing alloys by electrolysis of oxides of rare earth elements such as neodium, samarium, gadolinium, cerium, lanthanum, praceodymium, yttrium and europium have been known. However, there has been known no practical process of electrolysis of terbium oxides. It has been found by the present inventors that no satisfactory extent of reduction can be attained in the conventional electrolysis of a usual terbium oxide (Tb.sub.4 O.sub.7).
Although electrolysis of fluorides of terbium has been conducted to produce a terbium alloy or terbium metal (Japanese Patent Application Laid-Open (KOKAI) No. 62-224692(1987)), this process is not advantageous for industrial mass production since it requires, in this process, a superfluous step of fluorination of the terbium oxides. It has therefore been thought that a process which enables to obtain a sufficient amount of terbium alloys or terbium metal by a direct electrolysis of terbium oxides is industrially advantageous and desirable